Collision Course

Flight is a magnificent means of

transportation, allowing bats, insects,

birds and even humans to travel great

distances. For many birds, however, a

journey across the skies may be a

veritable obstacle course of humanrelated hazards. International

Migratory Bird Day (IMBD) is an

opportunity to examine the obstacles

birds may encounter in flight and

explore the many ways we may

minimize their impacts.

The towers erected for our cell phones

and pagers, the lines that bring us power,

our vehicles, the windows on homes and

office buildings, and even sources of

renewable energy, such as wind turbines,

create obstacles for birds in flight.

Collisions with these obstacles may cause

the death of one bird or tens of

thousands of birds in a single incident.

Biologists estimate the combined

death toll from aerial collisions may

exceed 700 million birds each year and

affects all types, from ducks, gulls,

plovers, owls, and hawks, to woodpeckers, hummingbirds, warblers,

sparrows, and finches.

The problem is urgent, and biologists,

conservation organizations, communities and individuals are joining forces

with industry representatives to

unravel the causes of bird collisions

and to explore ways of making a bird’s

journey safer. Individual participation

in these efforts can have significant

results. Small changes at home,

involvement at work, and active

contribution to your community can

make a world of difference to bird

conservation.

Clear the Way for Birds!

IMBD Explores Bird Collisions

International

Migratory Bird

Day (IMBD),

held annually

on the second

Saturday in

May, is an

invitation to

celebrate and

support

migratory bird

conservation.

IMBD Information

web - http://birds.fws.gov/imbd

phone - 703 /358-2318

IMBD Materials

web - http://www.BirdDay.org

phone - 1-866/334-3330

March 2005

Power Lines

Birds with large wingspans, such as raptors,

cranes, and swans, are less maneuverable

and thus most vulnerable to collisions with

power lines. The impacts may be especially

high when power lines are located near

marshes, lakes, and other habitats where

birds congregate in winter, when breeding,

or on migration. Wind and stormy weather

also make avoiding lines a challenge. New

guidelines that are used by utility companies are helping to lower the impact of

power lines on birds.

Solutions ~ Burying power lines eliminates

bird collisions. Flags or marker balls on

lines located above ground help to increase

their visibility, helping birds to see and avoid

them. When lines are parallel, the likelihood

that birds will see one line and avoid it only

to hit another are decreased.

In the IMBD 2005 artwork, David Sibley portrays collision

hazards using an illusion of depth and layers: a selection of birds

risks striking a plate glass window, in which is mirrored an array

of other birds against a crowded skyline of aerial obstacles.
Communication Towers

Communication towers provide coverage

for cell phones, pagers, television and radio

— technologies that are central to our

lives. Over 140,000 towers are located in the

United States, and as many as 5,000 new

towers are erected each year. Bird collisions at towers have been reported for over

50 years, and studies are ongoing to

determine the causes and solutions. The

towers that are the most hazardous to

birds are those that are over 200 feet, are

illuminated at night with red lights,

are supported by guy wires, and are

located in migration corridors, near

wetlands and in areas prone to fog, low

clouds, and precipitation. Birds that

migrate at night are drawn to tower lights,

especially in poor weather. Disoriented,

they circle the area, eventually striking the

guy wires, the tower, or even one another.

Solutions ~ Birds are less likely to be

harmed by shorter structures that do not

require lighting or guy wires, lights that

are white or green, and towers that are

located away

from migration corridors and cloudy areas.

Creative placement of new towers includes

using existing buildings.

Wind Turbines

Harnessing the wind’s energy is an

economical means of producing electricity.

As early as 200 B.C., windmills were used

to pump water and grind grain. Today, wind

farms may include hundreds of turbines,

tall structures which support fan-like

rotors connected to generators. The

electricity produced by the spinning rotors

supplies power to towns and cities. Like

communication towers, turbines are most

harmful to migrating birds on cloudy

nights and when turbine height requires

the use of lights. Because turbines are not

supported by guy wires and rarely involve

lights, their impact on birds in flight

compared to other structures

is relatively low.

Solutions ~ Proposals for new wind farms

that consider bird migration routes, bird

abundance, and turbine height will help to

minimize fatalities.

Plate Glass

One of the greatest hazards to birds is

plate glass, with windows in homes and

offices killing as many as one billion birds

each year. Glass is invisible to birds, and if

it reflects the images of trees, bushes, the

sky or other natural habitat, a bird may fly

directly into it. The presence of houseplants behind windows, the distance of

vegetation or bird feeders from windows,

and the angle of reflection may all influence

the likelihood of a bird flying into glass.

Studies indicate that one of every two

strikes is fatal. If not killed outright, birds

stunned after striking glass often fall prey

to hawks, dogs, cats, raccoon, and even

squirrels. In addition, tall buildings and

vanity signs that remain lit throughout the

night are as hazardous as lighted towers.

Birds may be attracted to these structures, confused by the lights, and circle

repeatedly, dying of exhaustion or by

colliding with the building.

Solutions ~ There are many ways to

reduce bird strikes at windows.

• Hang ribbons, wind chimes, or hawk

silhouettes the full length of the glass

outside windows, using a suction cup.

Movement is more effective in deterring

birds than static images on the glass.

• Move house plants away from windows.

• Place bird feeders, birdbaths, and plants

less than half a meter from windows, so

that birds are less likely to build up

enough momentum to harm themselves.

• Close curtains and blinds whenever

possible.

• Use window films that lessen the glare

and transparency of glass.

• Extinguish building lights or draw blinds

from dusk until dawn.

Transportation

Travel by air and car is a convenience that

is relatively safe for humans, but results in

death for as many as 2 million birds each

year. The over 8 million miles of roads in

the U.S. and hundreds of airports are often

bordered by fences and vegetation, which

are used by birds for perching, foraging,

and nesting. The heat emitted by road and

runway surfaces, puddles that form beside

roads, and the salt used for de-icing are

just a few of the other factors that attract

birds. Collisions with cars are also influenced by location of the road, proximity of

vegetation, and vehicle speed.

Solutions ~ Erect road signs or speed

bumps to lower vehicle speeds where bird

activity is frequent and remove plants from

roadsides and medians that attract birds.

Landscaping with taller trees and bushes

will cause birds to fly higher. Better

planning of new roads and highways

will benefit birds by avoiding valuable

habitats.

For More Information on Bird Collision Issues:

American Bird Conservancy Wind Energy Policy - www.abcbirds.org

Avian Power Line Interaction Committee - www.aplic.org

Birds & Buildings - www.birdsandbuildings.org/index1024.html

Fatal Light Awareness Program - www.flap.org

National Wind Coordinating Committee - www.nationalwind.org

U.S. Fish & Wildlife Service - http://migratorybirds.fws.gov/issues